Internal combustion engine



June 12, 1962 s. M. DOBROSAVLJEVIC 3,03 5

' V INTERNAL COMBUSTION ENGINE Filed June 13, 1960 2 Sheets-Sheet 1 June 12,-1962 DO-BROSAVLJEVIC 3,038,455

INTERNAL COMBUSTION ENGINE Filed Jfine is, 1960 I 2 Sheets-Sfieet 2 I I [1 I I I 7L m, x L; X l"' Q 8/ W ...i I i 23. ,y I l 1 If. /4

T 1, I12 {I //v VENTOR Slobodan mzroaleosAwe-w 3,938,455 INTERNAL CMBUSTlN ENGENE Siohodan M. Dohresavljevic, Perside Milenitovic, Belgrade, Yugoslavia Filed lune 13, Well, Ser. No. 35,482 Clmxns priority, application Yugoslavia June 12, 1959 19 Claims. (Cl. 123-32) The present invention relates to an internal combustion engine, especially to an air-cooled injection-type internal combustion engine provided with an air channel extending through the cylinder head and having wall portions extending in a divergent-convergent manner with respect to each other below which is arranged a combustion chamher, the gas exchange of which is controlled by mean of a common inlet and outlet valve.

With the known constructions of this type, the common channel conducting the fresh air and exhaust gases extends through the cylinder head with an essentially constant cross section. In order to prevent backfiring of the released or discharged exhaust gases from the combustion chamber into the portion of the air channel conducting fresh air to the combustion chamber, the prior art construction had to be operated with a large excess amount of air requiring a larger power output of the air blower. Since the quantity of air supplied by the blower is proportionally dependent on the engine output, it is impossible to prevent in these prior art constructions the backfiring of a part of the exhaust gases into the air channel at relatively low engine rotational speeds which causes the engine to run irregularly.

According to the present invention, these disadvantages of the prior art are effectively avoided and eliminated by providing within the air channel a deflection member located ahead of the valve, as viewed in the direction of air flow with the combustion air flowing off along both sides of the deflection member whereby the exhaust gases are deflected by the rear side of the deflection member in the direction toward the discharge aperture of the air channel.

A completely satisfactor unobjectionable flow condition results from the use of such a deflection member already with .a relatively slight excess quantity of air in respect to the fresh air to be introduced into the cornbustion space as well as in respect to the exhaust-gas flow flowing out of the combustion chamber, whereby an even operation of the engine over the entire rotational speed range is attained thereby. Especially by reason of the fact that the deflection member is arranged symmetrically at a distance ahead of the inlet aperture of the air into the combustion chamber and by reason of the provision of a trough-shaped depression or recess on the rear side of the deflection member, there is avoided with certainty, owing to the forced acceleration of the air resulting therefrom, that the exhaust gases reach the part of the air channel through which the fresh air is conducted whereby the rotational speed of the engine may also be increased.

In addition to a good degree of filling of the cylinder, the released gases are simultaneously guided or conducted therewith by the troughshaped configuration on the rear side of the deflection body as an organized directed stream in the direction toward the outlet aperture of the air channel. The deflection member is arranged advantageously within the region of the largest channel cross section at the same distance with respect to the channel walls arranged divergently-convergently to each other. Furthermore, an effective cooling of the hottest part of the cylinder head within the area of the exhaust gas flow is achieved by means of the air quantity forced laterally past the deflection member.

aired btates t tent It is also possible to form the deflection member as a conically-shaped form-part which is arranged, angularly bent in a spiral shaped manner, eccentrically ahead of the inlet aperture of the combustion chamber which itself is disposed in the plane of symmetry of the air channel. Such an arrangement is particularly suited for constructions in which the combustion chamber is arranged in the cylinder axis and the common inlet and outlet valve extends essentially coaxially thereto. There is achieved, in addition to a favorable air flow combined with a high degree of filling of the cylinder, the additional advantage that combustion air enters with a circulatory motion into the combustion chamber and produces a unidirectional angular current of high intensity. This manner of operation may be enhanced by the fact that the conically-shaped deflection member is arranged freely exposed within the area of the largest channel cross section and is surrounded by the flow along the sides thereof of difierently large partial air quantities. The combustion chamber is preferably formed by wall portions of annular bulged configuration having an axis of rotation arranged coaxially to the valve to which is coordinated a Venturi-shaped inlet aperture. Favorable flow conditions are created thereby in combination with the forced movement of the air caused by the deflection member for the realization of the combustion process within the combustion chamber.

In connection with a construction having a combustion chamber arranged at an angle to the cylinder axis, it is advantageous to arrange in the wall of the combustion chamber facing the injection nozzle a deflecting projection or nose portion having a cross sectional profile symmetrical with respect to the combustion chamber axis. A double vortex is produced thereby within the combustion chamber exclusively during the compression stroke of the operating cycle which favors the combustion mixture preparation.

Accordingly, it is an object of the present invention to provide an internal combustion engine of the type mentioned hereinabove which eliminates and obviates the deficiencies and shortcomings of the prior art devices.

Another object of the present invention resides in the provision of an internal combustion engine having a common inlet and outlet valve for each cylinder in which the danger of backfiring of the combustion gases into the air channel conducting the fresh air to the combustion chambers is essentially precluded.

A further object of the present invention resides in the provision of simple means effectively preventing backfiring of the engine in discharging a part of the exhaust gases into the fresh air intake duct through the common inlet and outlet valve during the operation of the engine.

A further object of the present invention resides in the provision of an arrangement for the control of the flow of the combustion air and exhaust gases in an internal combustion engine which is simple in construction, relatively inexpensive in manufacture and which increases the combustion efficiency of the engine.

A further object of the present invention resides in the provision of a deflection member arranged within the air channel through which the fresh air is conducted to the combustion space and through which the exhaust gases are discharged into the atmosphere which reduces the necessary load on the engine required by the necessitated blower output supplying the combustion air.

Still a further object of the present invention resides in the provision of an internal combustion engine with control means of simple nature for controlling the flow of combustion air and exhaust gases in such a manner by means of a common intake and exhaust valve as to increase the combustion efliciency of the engine and produce a higher degree of filling of the cylinder space.

Another object of the present invention resides in the provision of a flow control structure controlling the flow of the combustion air in such a manner as to produce a high degree of eddying of the combustion air within the combustion space.

These and other objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing, which shows, for purposes of illustration only, two embodiments in accordance with the present invention and wherein:

FIGURE 1 is a longitudinal cross-sectional view taken through the plane of symmetry of the cylinder head of an air-cooled internal combustion engine together with the surrounding parts thereof in accordance with the present invention,

FIGURE 2 is a cross-sectional view taken along line II-II of FIGURE 1 whereby, for sake of clarity, the control parts of the engine have not been illustrated,

FIGURE 3 is a partial cross-sectional view through the combustion chamber of the construction of FIGURE 1 taken essentially in the plane illustrated by the line IIIIII of FIGURE 1,

FIGURE 4 is a longitudinal cross-sectional view through the cylinder head of an air-cooled combustion engine provided with a modified embodiment of a deflection member in accordance with the present invention, and

FIGURE 5 is a cross-sectional View taken along line VV of FIGURE 4.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate corresponding parts, reference numeral 1 designates in FIGURE 1 the working cylinder of an air-cooled internal combustion engine in which a piston 2 is adapted to reciprocate. A cylinder head 3 is secured on the top of the working cylinder 1. The top side 4 of cylinder head 3 forms a dish-shaped recess 5. A rocker arm 6 is pivotally supported within the trough-shaped recess 5 which rocker arm 6, reciprocated by the push-rod 7, actuates the common inlet and outlet valve 8. The valve 8 is thereby arranged at an angle to the cylinder axis and controls the inlet and outlet of aperture 9 of the combustion chamber 19. The combustion chamber 10 is arranged coaxially to the valve 8 and is formed by walls 11 of ananular bulge shape adjoined by an overflow channel or communicating passage 12 which discharges into or terminates in the main combustion space 13. For purposes of introducing the fuel into the combustion chamber 10, an injection nozzle 14 is provided which may be of any suitable known construction. A nose portion or projection 15 of symmetrically shaped cross section is arranged in the wall 11 of the combustion chamber 10* opposite the injection nozzle 14. An air channel 16 extending through the entire cylinder head 3 is arranged within the plane of symmetry XX of the cylinder head 3 above the combustion chamber 10, the walls 17 and 17 of which steadily widen within the partial area 18 of the channel 16 and steadily narrow Within the partial area 18' (FIGURE 2) in the direction toward the discharge aperture 19. The largest cross section of the channel 16 is disposed in the plane YY (FIGURE 2) of the valve 8.

An essentially cylindrically-shaped deflection member 20 is arranged within the air channel 16 ahead of the plane YY of the valve, as viewed in the direction of flow of the combustion air, the crown or apex 21 of which is disposed at a distance above the aperture 9 leading to the combustion chamber ltl. The deflection member 20 is integral with the cylinder head 3 and extends into the channel 16 in the plane of symmetry XX thereof in such a manner that there remains the same distance from the deflecting body 20 to both channel walls 17 and 17. The deflection member 20 is provided on the rear side thereof with a trough-shaped recess or depression 22 4 which extends over the entire length of the deflection member 2%") and proceeds in the direction of the aperture 9 of the combustion chamber 10.

During operation of the engine, an air stream a (FIG- URE 2) is supplied or introduced into the channel 16 by means of the cooling blower of any conventional construction (not illustrated) whereby the air stream flows around the deflection member 20 in two partial air streams a and a" and thereupon flows off into the atmosphere through the discharge aperture 19. During suction stroke of the engine, the valve 8 opens up the Venturi-shaped inlet aperture 9 whereupon the accelerated air introduced into the channel 16 enters into the combustion chamber 10 in which a double vortex builds up by reason of the deflection nose portion 15 as indicated by the arrows b in FIGURE 3. Fuel is injected into this double vortex b through the injection nozzle 14 and is brought to combustion by self-ignition. The expanding mixture is displaced by the piston 2 in the exhaust position of the valve 8 through the aperture 9 into the channel 16 and is deflected by the trough-shaped recess or depression 22 of the deflection body 20 into a directional, organized stream directed toward the discharge aperture 19. A relatively slight excess of air within the channel 16 thereby prevents in conjunction with the deflection body 20 that the exhaust gases reach the suction or intake portion 18 of the air channel 16. The wall portions 17 and 17' of the channel 16 are simultaneously cooled by means of the excess of air within channel 16.

FIGURES 4 and 5 illustrate a further embodiment of the gas exchange control according to the present invention which distinguishes itself from the embodiment of FIGURES l to 3 described hereinabove essentially by a combustion chamber arranged Within the cylinder axis and a deflection body eccentrically arranged with respect thereto The same parts are designated in FIGURES 4 and 5 by corresponding primed reference numerals.

A cylinder head 3 is again secured on top of the working cylinder 1 and a common inlet and outlet valve 8' is suspendingly arranged within cylinder head 3. The valve 8 extends coaxially to the working cylinder 1' and is actuated, in a manner known per se, by means of a push-rod 7' through a rocker arm 6'. The valve '8' controls a Venturi-shaped inlet aperture 9' of a combustion chamber 1% which is provided with a bulge-like annular wall portion 11' and with an overflow channel or communicating passage 12' which terminates in the main combustion space 13. An injection nozzle 14' of any suitable construction is again operatively connected with the combustion chamber 10. An air channel 16' which extends through the cylinder head 3 is provided above the combustion chamber 10", which air channel 16' extends through the cylinder head 3' in the plane of symmetry XX' thereof. The walls 17" and 17" are arranged in a converging-diverging manner corresponding to the arrangement thereof in the first-described embodiment. A deflection member 23 consisting of a stamped or pressed sheet-metal part of conical base shape is inserted within channel 16' in the plane Y'Y' ahead of the valve 8' and the inlet aperture 9 thereof. The deflection body member 23 has an angularly-bent spiral wall 24 and is secured or fastened within channel 16' with respect to the plane of symmetry XX in such a manner that different partial quantities of air flow along the two slides thereof.

The operation of the arrangement of the embodiment of FIGURES 4 and 5 corresponds essentially to that of the first-described embodiment of FIGURES 1 to 3 with the difference, however, that an angular momentum is imparted to the air introduced into the air channel 16' under a slight excess pressure during the suction stroke of the engine along the wall 24 of the deflection member 23 so that the combustion air enters into the combustion chamber 10' with an essentially circular movement. The movement of the air entrance is indicated in FIGURE 5 through the arrows c. By reason of such an arrangement, an intensive vortex formation results which accelerates and thereby favorably influences the combustion operation. The vortex formation may additionally be aided in both embodiments described herein by a suitable configuration of the bottom side 25 of the valve disk as illustrated in FIGURE 4.

While I have shown and described two embodiments in accordance with the present invention, it is understood that the same is not limited thereto. For example, the

present invention is not limited to air-cooled intern-a1 combustion engines, but is applicable with equal force to water-cooled engines whereby the necessary partial air stream may be branched off directly from the air stream supplied by the fan of the cooling system.

Thus, it is quite obvious that the present invention is not limited to the details shown and described herein, but is susceptible of many changes and modifications within the spirit and scope of the present invention and, I, therefore, do not wish to be limited tothe details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. An internal combustion engine comprising cylinder head means provided with air channel means having wall portions extending with respect to each other in a divergent-convergent manner, said air channel means terminating in a discharge aperture, combustion chamber means in said cylinder head means disposed approximately below said wall portions, control means for controlling the gas exchange of said combustion chamber means, and deflection means arranged within said air channel means ahead of said control means as viewed in the flow direction, said deflection means being so arranged within said air channel means and in spaced relationship from the wall portions thereof that partial air flow quantities flow along both sides thereof directly to said discharge aperture and being provided on the rear side thereof with deflection surface means eflectively deflecting the exhaust gases in the direction of the discharge aperture of the air channel means.

2. An internal combustion engine comprising cylinder head means provided with air channel means extending therethrough and having a discharge aperture and wall portions extending with respect to each other in a divergent-convergent manner, combustion chamber means arranged approximately below said wall portions, common control valve means for controlling the gas exchange of said combustion chamber means and deflection means arranged Within said air channel means ahead of said control valve means as viewed in the flow direction, said debection means being between said wall portions of said air channel means that partial air flow quantities flow along both sides thereof directly to said discharge aperture and being provided on the rear side thereof with deflection surface means effectively deflecting the exhaust gases in the direction of the discharge aperture of said air channel means.

3. An internal combustion engine according to claim 2, wherein said deflection means is arranged symmetrically at a distance ahead of the inlet aperture of the air into said combustion chamber.

4. An internal combustion engine according to claim 3, wherein said deflection surface means is constituted by a trough-shaped depression provided on the rear side of said deflection means.

5. An internal combustion engine according to claim 1, wherein said deflection means is provided with an essentially trough-shaped recess on the rear side thereof constituting said deflection surface means.

6. An internal combustion engine comprising cylinder head means provided with air channel means having wall portions extending with respect to each other in a divergent-convergent manner, said air channel means terminating in a discharge aperture, combustion chamber means in said cylinder head means disposed approximately below said wall portions, control means for controlling the gas exchange of said combustion chamber means, and deflection means arranged within said air channel means ahead of said control means as viewed in the flow direction, said deflection means being so arranged within said air channel means and spaced from wall portions thereof so that partial air flow quantities flow along both sides thereof directly to said discharge aperture and being provided on the rear side thereof with deflection surface means effectively deflecting the exhaust gases in the direction of the discharge aperture of the air channel means, said deflection means being provided with an essentially trough-shaped recess on the rear side thereof constituting said deflection means, said deflection means being arranged in the area of the largest cross section of said air channel means and essentially centrally positioned between the divergent-convergent wall portions thereof.

7. An internal combustion engine according to claim 2, wherein said deflection means is arranged essentially symmetrically within said air channel means within the are-a thereof having maximum cross section and essentially at equal distances from said wall portions.

8. An internal combustion engine according to claim 2, wherein said deflection means is constituted by a conicallyshaped form part, which is arranged angularly bent in a spiral manner, eccentrically ahead of the inlet aperture of said combustion chamber means which is disposed in the plane of symmetry of said air channel means.

9. An internal combustion engine according to claim 8, wherein said comically-shaped deflection means is arranged freely exposed within the area of largest cross section of said channel means and diiferent partial air quantities flow along the sides thereof.

10. An internal combustion engine according to claim 2, further comprising injection means in the walls constituting said combustion chamber means for injecting fuel into said combustion chamber means, and wherein the walls constiuting said combustion chamber means are provided with a deflection nose portion having a crosssectional profile symmetrical to the combustion chamber axis.

11. An internal combustion engine according to claim 10, wherein said combustion chamber means is constituted by an annular bulge-like Wall disposed essentially coaxially with respect to said control valve means, and a Venturi-shaped inlet aperture leading from said air channel means into said combustion chamber means.

12. An internal combustion engine, especially an aircoled internal combustion engine of the injection type, comprising cylinder head means provided with air channel means extending therethrough, said air channel means defining an essentially straight air passage through said cylinder head means and having wall portions extending with respect to each other in a divergent-convergent manner, said air channel means terminating in a discharge aperture, combustion chamber means in said cylinder head means arranged essentially below said wall portions, common control means for controlling the gas interchange of said combustion chamber means and constituting common inlet and outlet valve means, and deflection means arranged within said air channel means ahead of said valve means as viewed in the normal direction of flow, said deflection means being spaced intermediate said wall portions and extending downwardly into said air channel means and terminating above the bottom of said air channel means so that partial air flow quantities flow laterally therealong on both sides and beneath said deflection means irrespective of the position of said control means, said deflection means being provided on the rear side thereof with deflection surface means eifectively deflecting the exhaust gases in the direction of the discharge aperture of said air channel means.

13. An internal combustion engine according to claim 7 .12, wherein said deflection means is arranged at a distance symmetrically ahead of the inlet aperture of the air into said combustion chamber means and is provided on the rear side thereof with an'essentially trough-shaped depres- SIOII.

14. An internal combustion engine according to claim 13, wherein said deflection means is arranged within the area of largest cross section of air channel means and is essentially centrally positioned between said divergentconvergent wall portions.

15. An internal combustion engine according to claim 12, wherein said deflection means is constituted by a conically-shaped form part which is arranged spirally-shaped, angularly-bent eccentrically ahead of the inlet aperture of said combustion chamber means disposed in the plane of symmetry of said air channel means.

16. An internal combustion engine according to claim 15, wherein said comically-shaped deflection means is arranged freely exposed within the area of the largest channel cross section and different quantities of air flow therealong laterally past both sides thereof.

17. An internal combustion engine according to claim.

16, further comprising injection means in the walls constituting said combustion chamber means, the walls constituting said combustion chamber means being provided with a deflecting nose portion opposite said injection means which is of essentially symmetrical cross section with respect to the axis of said combustion chamber means.

18. An internal combustion engine according to claim 2, wherein said deflection means terminates near said combustion chamber means and above the bottom of said air channel means whereby forced air may be passed through said air channel means beneath said deflection means.

19. An internal combustion engine according to claim 2, wherein said air channel means at least in regions immediately adjacent said deflection means comprise an essentially straight air passage.

References Cited in the file of this patent FOREIGN PATENTS 469,777 Great Britain Aug. 3, 1937 

